1. Field of the Invention
This invention relates generally to equipment and techniques suitable for communicating information graphically.
2. Background of the Invention
It is known in the art to utilize a slide projection screen, standard projection screen, overhead projection system or flip chart as a graphic aid in making a presentation of information in professional, sales, teaching and like fields. However, all of these systems are disadvantageously inflexible because they do not lend themselves to handwritten or hand-drawn modification during a presentation, of the information they are initially adapted to communicate--such modification reflecting, for instance, conceptual changes growing out of discussion and development of an initially presented theme or idea during a presentation, seminar, etc.
More specifically, slide projection equipment is a relatively rigid system not well-suited to "on the spot" modification of the subject matter set forth on the slide(s) because during such modification the image appearing on the screen is obscured by shadows caused by a hand, or head of the person modifying the projected image, or even by the implement used to make the modification. Standard projection equipment is unsuitable for analogous reasons.
The overhead projection system is similarly unsuitable. Due to the movement of the overlay during modification, the system provides an unstable image. Further, the scale of the working surface is typically confined to, at most, a twelve inch by twelve inch image.
A flip chart is likewise unsuitable because it offers limited means in which to update the studio-prepared material initially set forth. Further, the size of the image is fixed, which limits the flip chart's adaptability as a tool for presenting modifications clearly. Worse yet, changes to the information on the chart's pages, once made, are typically permanent, making difficult (if not infeasible) any further revision during the presentation--not to mention removal of the modification so as to return the pages to their initial state. The flip chart is thus, effectively, unusable for subsequent related presentations of the original data.
And, while use of a conventional rear projection screen system may diminish some of the aforementioned difficulties, it also is problematical. For example, the image presented on the screen is not well-defined and does not allow for accurate tracing of the projected image for artistic renderings of a real photographic image.